function initTopItemChart(){
	
	 var overallChart = echarts.init(document.getElementById('overallAnalyst'));
	  overallChart.showLoading({text: '正在努力的读取数据中...',});

			     $.ajax({
				    url: "data/getOverallTopItemsJson",
				    timeout: 5000,
				    success:function(res) {	

				    //alert(res);
				    var jsonRes = eval('(' + res + ')');
				    var legendData = new Array();
				    var i = 0;
				    for(var item in jsonRes){

				    	legendData[i]=jsonRes[item].name;
				    	i++;
				    } 
					var option = {
				    title : {
				        text: '语说：窥一斑而知全豹',
					 	subtext: '数据来自语说',
				        x:'center'
				    },
				    tooltip : {
				        trigger: 'item',
				        formatter: "{a} <br/>{b} : {c} ({d}%)"
				    },
				    legend: {
				        x : 'center',
				        y : 'bottom',
				        data:legendData
				    },
				    toolbox: {
				        show : true,
				        feature : {
				            mark : {show: true},
				            dataView : {show: true, readOnly: false},
				            restore : {show: true},
				            saveAsImage : {show: true}
				        }
				    },
				    calculable : true,
				    series : [
				        {
				            name:'语说数据',
				            type:'pie',
				            radius : [30, 110],
				            center : ['50%', 200],
				            roseType : 'area',
				            data:jsonRes
				        }
				        ] 
				     };
				    	//init the chart options
				      	overallChart.hideLoading();
					     overallChart.setOption(option);

				    },
				    error:function(){
				    	overallChart.showLoading({text: '获取数据过程中发生异常'});
				    }
				  }); 
	    	
}